New research suggests a surprising benefit to getting snipped—but here's why we're skeptical

Ever consider getting snipped as an adult? Probably not—that sounds painful. Yet according to a new study from the University of Quebec, guys who got circumcised after age 35 had a 45 percent lower risk of prostate cancer versus those who kept their penises in tact. The association was strongest among African American men, who have the highest risk of prostate cancer in general.

Surprisingly, circumcision doesn't hurt as much as you think, and is a regular outpatient procedure, says Men's Health's urology advisor, Larry Lipshultz, M.D., of Baylor College of Medicine. Still, that doesn’t mean you should get snipped now just to protect against prostate cancer. The researchers say they actually don’t know what made the men get surgery in the first place.

However, it’s safe to assume that something was bothering the guys enough to send them to the doctor, like sexually transmitted infections (STIs), Dr. Lipshultz speculates. Skin folds can harbor infections more readily, increasing your risk of getting and spreading STDs—which have been linked to cancer in men. One 2005 meta-analysis found that men who had a history of STDs had 48 percent higher odds of developing prostate cancer.

What’s interesting is that the new study found that men who got circumcised as infants didn’t have any protection against prostate cancer. That makes sense, says Marvin Wang, M.D., codirector of neonatology and newborn services at MassGeneral Hospital for Children. Doctors encourage circumcision in infancy for other reasons: It decreases risk of urinary tract infections in the baby’s first year, and reduces the chances of penile cancer and transmission of STIs, particularly HIV, Dr. Wang says.

So nope, there’s nothing magical about age 35. And if this study was done in a healthy population, you might get different results. (In other words, more research is needed.) The only time you might think about getting circumcised: If you're suffering from recurrent STDs, you might owe it to your partners to avoid giving them infections, says Dr. Lipshultz.

Bottom line: Stick with what’s known for lowering your prostate cancer risk: eat a heart-healthy diet, exercise regularly, and maintain a healthy weight. It's the usual advice, but it works—and you can keep your penis just the way you like it.